Lasers, LEDs and light sources are devices that create light. LEDs (light emitting diodes) convert an electrical current into light using spontaneous emission in optically active semiconductors.

In some people that are photosensitive, UV light from sunlight and indoor light sources can trigger a lupus flare. In addition to sunlight, ultraviolet rays are also given off by several different ...

[Oneironaut] sent us another IR hack. This time it is a writeup on the best ways to create IR light sources from regular lights. Since normal flashlight bulbs emit a broad enough spectrum to ...

A source of light makes light. The Sun and other stars, fires, torches and lamps all make their own light and so are examples of sources of light. Some animals, such as fireflies and glow-worms ...